As users are now inbox-notified for each review suspension, there is now one edge case that may cause confusion to users --
Background
On Stack Overflow, we have users1 who have over 50 previous review suspensions, and moderators have previously sent such reviewers with poor review histories away with a manually-applied "permanent"2 review suspension with this message:
Due to your poor review history as well as no signs of improvement after many review suspensions, you won't be able to use any of the review queues on the site any longer.
Issues
As durations for manual review suspensions are capped at 365 days, moderators have to occasionally revisit the current suspensions and reapply a new 365-day review suspension with the same message, to ensure that the "permanent" review suspension remains permanent.
Image below: Shows the final step of the mod form to manually review suspend a user, maximum allowed is 365 days (while there is no limit when user is suspended for failing audits)
This now may cause confusion to the "permanently"-review suspended users with the recent change to notify users with each review suspension, as there was no new review action taken by them to get a new review suspension, while still getting a notification for each renewal in the inbox, reminding them that they are still review suspended.
Image below: Shows the review suspension history of a user, and that they see the permanent review suspension renewal notice. This UI has been supplemented with Sam's UserReviewBanHelper userscript to show time taken for viewing of review suspension notices.
Also, the steps taken to manually-unsuspend and re-suspend with the same message is quite tedious (no joke), and due to this, moderators do not actually care about monitoring and renewing permanent review suspensions. I have written a userscript that currently does the renewal in one click, but this only works for as long as I'm a moderator on Stack Overflow.
Image below: Shows one user in the list of currently review suspended users, who has a manual permanent review suspension, and the button added by Sam's UserReviewBanHelper userscript which allows mods to reapply the manual permanent review suspension in one click.
Feature Request
Please allow moderators to apply permanent review suspensions (as opposed to manually renewing 365-day suspensions).
Footnotes:
1 At time of post, Stack Overflow has 33 such users, as tracked in my Stack Overflow Review Ban Stats spreadsheet.
2 "permanent" is not truly permanent, as it's just a manually-applied and manually-renewed review suspension and can accidentally expire like all review suspensions if no moderators remember to perform the renewing ritual.